Table 1. Studies divided into 5 groups based on research activity levels.

Group	Number of Studies	Range of Activity Levels in Each Group			Total Number of Positive & Negative Studies		Number of Published Studies
		Minimum	Median	Maximum	Positive	Negative	Positive	Negative
1	22	0	7.0	17	7	15	5	7
2	22	18	30.5	57	9	13	9	11
3	22	58	88.0	128	9	13	7	11
4	22	130	265.0	504	14	8	14	2
5	22	538	1829.0	2058	19	3	19	1